X-Git-Url: http://nsz.repo.hu/git/?a=blobdiff_plain;f=ir%2Fbe%2Fbelive.c;h=505546f20d8a4fe83be1fcd2175cc566691e5c9c;hb=48f0393daa5d5a14ed7e3e32ee2b090759c9371e;hp=ae6940a3daf4577c0fe603cf74981e32e29adf86;hpb=5d001fc14a7d4ef4926012a9b5864341bac35066;p=libfirm

diff --git a/ir/be/belive.c b/ir/be/belive.c
index ae6940a3d..505546f20 100644
--- a/ir/be/belive.c
+++ b/ir/be/belive.c
@@ -11,35 +11,285 @@
 #include "iredges_t.h"
 #include "irgwalk.h"
 #include "irprintf_t.h"
+#include "irbitset.h"
+#include "irdump_t.h"
 
 #include "beutil.h"
 #include "belive_t.h"
+#include "besched_t.h"
 
-FIRM_IMPL2(is_live_in, int, const ir_node *, const ir_node *)
-FIRM_IMPL2(is_live_out, int, const ir_node *, const ir_node *)
-FIRM_IMPL2(is_live_end, int, const ir_node *, const ir_node *)
+#define DBG_MODULE              "firm.be.liveness"
 
-/** The offset of the liveness information in a firm node. */
-size_t live_irg_data_offset = 0;
+#define LV_STD_SIZE             128
+#define LV_USE_BINARY_SEARCH
+#undef  LV_INTESIVE_CHECKS
 
-void be_liveness_init(void)
+static INLINE int is_liveness_node(const ir_node *irn)
 {
-  live_irg_data_offset = register_additional_graph_data(sizeof(irn_live_t));
+	switch(get_irn_opcode(irn)) {
+	case iro_Block:
+	case iro_Bad:
+	case iro_End:
+		return 0;
+	default:;
+	}
+
+	return 1;
 }
 
-static INLINE void mark_live_in(ir_node *block, const ir_node *irn)
+int (be_lv_next_irn)(const struct _be_lv_t *lv, const ir_node *bl, unsigned flags, int i)
 {
-  _get_or_set_live(block, irn, live_state_in);
+	return _be_lv_next_irn(lv, bl, flags, i);
 }
 
-static INLINE void mark_live_out(ir_node *block, const ir_node *irn)
+const ir_node * (be_lv_get_irn)(const struct _be_lv_t *lv, const ir_node *bl, int i)
 {
-  _get_or_set_live(block, irn, live_state_out | live_state_end);
+	return _be_lv_get_irn(lv, bl, i);
 }
 
-static INLINE void mark_live_end(ir_node *block, const ir_node *irn)
+int (be_is_live_in)(const be_lv_t *lv, const ir_node *block, const ir_node *irn)
 {
-  _get_or_set_live(block, irn, live_state_end);
+	return _be_is_live_xxx(lv, block, irn, be_lv_state_in);
+}
+
+int (be_is_live_out)(const be_lv_t *lv, const ir_node *block, const ir_node *irn)
+{
+	return _be_is_live_xxx(lv, block, irn, be_lv_state_out);
+}
+
+int (be_is_live_end)(const be_lv_t *lv, const ir_node *block, const ir_node *irn)
+{
+	return _be_is_live_xxx(lv, block, irn, be_lv_state_end);
+}
+
+
+#ifdef LV_USE_BINARY_SEARCH
+static INLINE unsigned _be_liveness_bsearch(struct _be_lv_info_t *arr, unsigned idx)
+{
+	struct _be_lv_info_t *payload = arr + 1;
+
+	unsigned n   = arr[0].u.head.n_members;
+	unsigned res = 0;
+	int lo       = 0;
+	int hi       = n;
+
+	if(n == 0)
+		return 0;
+
+#if 0
+	if(idx < payload[0].u.node.idx)
+		return 0;
+
+	if(idx > payload[n - 1].u.node.idx)
+		return n - 1;
+#endif
+
+	/* start a binary search for the requested node. */
+	while(lo < hi) {
+		int md          = lo + ((hi - lo) >> 1);
+		unsigned md_idx = payload[md].u.node.idx;
+
+		if(idx > md_idx)
+			lo = md + 1;
+		else if(idx < md_idx)
+			hi = md;
+		else {
+			res = md;
+			assert(payload[res].u.node.idx == idx);
+			break;
+		}
+
+		res = lo;
+	}
+
+#ifdef LV_INTESIVE_CHECKS
+	{
+		unsigned i;
+		for(i = res; i < n; ++i)
+			assert(payload[i].u.node.idx >= idx);
+
+		for(i = 0; i < res; ++i)
+			assert(payload[i].u.node.idx < idx);
+	}
+#endif
+
+	return res;
+}
+
+#else
+
+/**
+ * This function searches linearily for the node in the array.
+ */
+static INLINE unsigned _be_liveness_bsearch(struct _be_lv_info_t *arr, unsigned idx) {
+	unsigned n  = arr[0].u.head.n_members;
+	unsigned i;
+
+	for(i = 0; i < n; ++i) {
+		if(arr[i + 1].u.node.idx == idx)
+			return i;
+	}
+
+	return i;
+}
+#endif
+
+struct _be_lv_info_node_t *be_lv_get(const struct _be_lv_t *li, const ir_node *bl, const ir_node *irn)
+{
+	struct _be_lv_info_t *irn_live = phase_get_irn_data(&li->ph, bl);
+
+	if(irn_live) {
+		unsigned idx = get_irn_idx(irn);
+
+		/* Get the position of the index in the array. */
+		int pos = _be_liveness_bsearch(irn_live, idx);
+
+		/* Get the record in question. 1 must be added, since the first record contains information about the array and must be skipped. */
+		struct _be_lv_info_node_t *res = &irn_live[pos + 1].u.node;
+
+		/* Check, if the irn is in deed in the array. */
+		if(res->idx == idx)
+			return res;
+	}
+
+	return NULL;
+}
+
+static struct _be_lv_info_node_t *be_lv_get_or_set(struct _be_lv_t *li, ir_node *bl, ir_node *irn)
+{
+	struct _be_lv_info_t *irn_live = phase_get_or_set_irn_data(&li->ph, bl);
+
+	unsigned idx = get_irn_idx(irn);
+
+	/* Get the position of the index in the array. */
+	unsigned pos = _be_liveness_bsearch(irn_live, idx);
+
+	/* Get the record in question. 1 must be added, since the first record contains information about the array and must be skipped. */
+	struct _be_lv_info_node_t *res = &irn_live[pos + 1].u.node;
+
+	/* Check, if the irn is in deed in the array. */
+	if(res->idx != idx) {
+		struct _be_lv_info_t *payload;
+		unsigned n_members = irn_live[0].u.head.n_members;
+		unsigned n_size    = irn_live[0].u.head.n_size;
+		unsigned i;
+
+		if(n_members == n_size - 1) {
+			unsigned new_size = 2 * n_size * sizeof(irn_live[0]);
+			struct _be_lv_info_t *nw = phase_alloc(&li->ph, new_size);
+			memcpy(nw, irn_live, new_size);
+			nw[0].u.head.n_size = new_size;
+			irn_live = nw;
+			phase_set_irn_data(&li->ph, irn, nw);
+		}
+
+		payload = &irn_live[1];
+		for(i = n_members; i > pos; --i) {
+			payload[i] = payload[i - 1];
+		}
+
+		++irn_live[0].u.head.n_members;
+
+		res = &payload[pos].u.node;
+		res->idx    = idx;
+		res->flags  = 0;
+	}
+
+#ifdef LV_INTESIVE_CHECKS
+	{
+		unsigned i;
+		unsigned n = irn_live[0].u.head.n_members;
+		unsigned last = 0;
+		struct _be_lv_info_t *payload = &irn_live[1];
+
+		for(i = 0; i < n; ++i) {
+			assert(payload[i].u.node.idx >= last);
+			last = payload[i].u.node.idx;
+		}
+	}
+#endif
+
+	return res;
+}
+
+/**
+ * Removes a node from the list of live variables of a block.
+ * @return 1 if the node was live at that block, 0 if not.
+ */
+static int be_lv_remove(struct _be_lv_t *li, ir_node *bl, ir_node *irn)
+{
+	struct _be_lv_info_t *irn_live = phase_get_irn_data(&li->ph, bl);
+
+	if(irn_live) {
+		unsigned n   = irn_live[0].u.head.n_members;
+		unsigned idx = get_irn_idx(irn);
+		unsigned pos = _be_liveness_bsearch(irn_live, idx);
+		struct _be_lv_info_t *payload  = irn_live + 1;
+		struct _be_lv_info_node_t *res = &payload[pos].u.node;
+
+		/* The node is in deed in the block's array. Let's remove it. */
+		if(res->idx == idx) {
+			unsigned i;
+
+			for(i = pos + 1; i < n; ++i)
+				payload[i - 1] = payload[i];
+
+			payload[n - 1].u.node.idx   = 0;
+			payload[n - 1].u.node.flags = 0;
+
+			--irn_live[0].u.head.n_members;
+			DBG((li->dbg, LEVEL_3, "\tdeleting %+F from %+F at pos %d\n", irn, bl, pos));
+			return 1;
+		}
+	}
+
+	return 0;
+}
+
+static void register_node(be_lv_t *lv, const ir_node *irn)
+{
+	unsigned idx = get_irn_idx(irn);
+	if(idx >= bitset_size(lv->nodes)) {
+		bitset_t *nw = bitset_malloc(2 * idx);
+		bitset_copy(nw, lv->nodes);
+		bitset_free(lv->nodes);
+		lv->nodes = nw;
+	}
+
+	bitset_set(lv->nodes, idx);
+}
+
+/**
+ * Mark a node as live-in in a block.
+ */
+static INLINE void mark_live_in(be_lv_t *lv, ir_node *block, ir_node *irn)
+{
+	struct _be_lv_info_node_t *n = be_lv_get_or_set(lv, block, irn);
+	DBG((lv->dbg, LEVEL_2, "marking %+F live in at %+F\n", irn, block));
+	n->flags |= be_lv_state_in;
+	register_node(lv, irn);
+}
+
+/**
+ * Mark a node as live-out in a block.
+ */
+static INLINE void mark_live_out(be_lv_t *lv, ir_node *block, ir_node *irn)
+{
+	struct _be_lv_info_node_t *n = be_lv_get_or_set(lv, block, irn);
+	DBG((lv->dbg, LEVEL_2, "marking %+F live out at %+F\n", irn, block));
+	n->flags |= be_lv_state_out | be_lv_state_end;
+	register_node(lv, irn);
+}
+
+/**
+ * Mark a node as live-end in a block.
+ */
+static INLINE void mark_live_end(be_lv_t *lv, ir_node *block, ir_node *irn)
+{
+	struct _be_lv_info_node_t *n = be_lv_get_or_set(lv, block, irn);
+	DBG((lv->dbg, LEVEL_2, "marking %+F live end at %+F\n", irn, block));
+	n->flags |= be_lv_state_end;
+	register_node(lv, irn);
 }
 
 /**
@@ -52,33 +302,36 @@ static INLINE void mark_live_end(ir_node *block, const ir_node *irn)
  * @param is_true_out Is the node real out there or only live at the end
  * of the block.
  */
-static void live_end_at_block(ir_node *def, ir_node *block,
-    pset *visited, int is_true_out)
+static void live_end_at_block(be_lv_t *lv, ir_node *def, ir_node *block, bitset_t *visited, int is_true_out)
 {
-  mark_live_end(block, def);
-  if(is_true_out)
-    mark_live_out(block, def);
-
-  if(!pset_find_ptr(visited, block)) {
+	mark_live_end(lv, block, def);
+	if(is_true_out)
+		mark_live_out(lv, block, def);
 
-    pset_insert_ptr(visited, block);
+	if(!bitset_contains_irn(visited, block)) {
+		bitset_add_irn(visited, block);
 
-    /*
-     * If this block is not the definition block, we have to go up
-     * further.
-     */
-    if(get_nodes_block(def) != block) {
-      int i, n;
+		/*
+		* If this block is not the definition block, we have to go up
+		* further.
+		*/
+		if(get_nodes_block(def) != block) {
+			int i, n;
 
-      mark_live_in(block, def);
+			mark_live_in(lv, block, def);
 
-      for(i = 0, n = get_irn_arity(block); i < n; ++i)
-        live_end_at_block(def, get_nodes_block(get_irn_n(block, i)), visited, 1);
-    }
+			for(i = 0, n = get_Block_n_cfgpreds(block); i < n; ++i)
+				live_end_at_block(lv, def, get_Block_cfgpred_block(block, i), visited, 1);
+		}
 
-  }
+	}
 }
 
+struct _lv_walker_t {
+	be_lv_t *lv;
+	void *data;
+};
+
 /**
  * Liveness analysis for a value.
  * This functions is meant to be called by a firm walker, to compute the
@@ -86,86 +339,397 @@ static void live_end_at_block(ir_node *def, ir_node *block,
  * @param irn The node (value).
  * @param env Ignored.
  */
-static void liveness_for_node(ir_node *irn, void *env)
+static void liveness_for_node(ir_node *irn, void *data)
 {
-  const ir_edge_t *edge;
-  ir_node *def_block;
-  pset *visited;
+	struct _lv_walker_t *walker = data;
+	be_lv_t *lv       = walker->lv;
+	bitset_t *visited = walker->data;
+	const ir_edge_t *edge;
+	ir_node *def_block;
+
+	/* Don't compute liveness information for non-data nodes. */
+	if(!is_liveness_node(irn))
+		return;
+
+	bitset_clear_all(visited);
+	def_block = get_nodes_block(irn);
+
+	/* Go over all uses of the value */
+	foreach_out_edge(irn, edge) {
+		ir_node *use = edge->src;
+		ir_node *use_block;
+
+		/*
+		 * If the usage is no data node, skip this use, since it does not
+		 * affect the liveness of the node.
+		 */
+		if(!is_liveness_node(use))
+			continue;
+
+		/* Get the block where the usage is in. */
+		use_block = get_nodes_block(use);
+
+		/*
+		 * If the use is a phi function, determine the corresponding block
+		 * through which the value reaches the phi function and mark the
+		 * value as live out of that block.
+		 */
+		if(is_Phi(use)) {
+			ir_node *pred_block = get_Block_cfgpred_block(use_block, edge->pos);
+			live_end_at_block(lv, irn, pred_block, visited, 0);
+		}
+
+		/*
+		 * Else, the value is live in at this block. Mark it and call live
+		 * out on the predecessors.
+		 */
+		else if(def_block != use_block) {
+			int i, n;
+
+			mark_live_in(lv, use_block, irn);
+
+			for(i = 0, n = get_Block_n_cfgpreds(use_block); i < n; ++i) {
+				ir_node *pred_block = get_Block_cfgpred_block(use_block, i);
+				live_end_at_block(lv, irn, pred_block, visited, 1);
+			}
+		}
+	}
+}
 
-  /* Don't compute liveness information for non-data nodes. */
-  if(!is_data_node(irn))
-    return;
+static void lv_remove_irn_walker(ir_node *bl, void *data)
+{
+	struct _lv_walker_t *w = data;
+	be_lv_t *lv  = w->lv;
+	ir_node *irn = w->data;
+	be_lv_remove(lv, bl, irn);
+}
 
-  visited = pset_new_ptr(512);
-  def_block = get_nodes_block(irn);
+static const char *lv_flags_to_str(unsigned flags)
+{
+	static const char *states[] = {
+		"---",
+		"i--",
+		"-e-",
+		"ie-",
+		"--o",
+		"i-o",
+		"-eo",
+		"ieo"
+	};
+
+	return states[flags & 7];
+}
 
-  /* Go over all uses of the value */
-  foreach_out_edge(irn, edge) {
-    ir_node *use = edge->src;
-    ir_node *use_block;
+static void lv_dump_block(void *context, FILE *f, const ir_node *bl)
+{
+	if(is_Block(bl)) {
+		be_lv_t *lv = context;
+		struct _be_lv_info_t *info = phase_get_irn_data(&lv->ph, bl);
+
+		fprintf(f, "liveness:\n");
+		if(info) {
+			unsigned n = info[0].u.head.n_members;
+			unsigned i;
+
+			for(i = 0; i < n; ++i) {
+				struct _be_lv_info_node_t *n = &info[i+1].u.node;
+				ir_fprintf(f, "%s %+F\n", lv_flags_to_str(n->flags), get_idx_irn(lv->irg, n->idx));
+			}
+		}
+	}
+}
+
+static void *lv_phase_data_init(phase_t *phase, ir_node *irn, void *old)
+{
+	struct _be_lv_info_t *info = phase_alloc(phase, LV_STD_SIZE * sizeof(info[0]));
+	memset(info, 0, LV_STD_SIZE * sizeof(info[0]));
+	info[0].u.head.n_size = LV_STD_SIZE - 1;
+	return info;
+}
 
-    /*
-     * If the usage is no data node, skip this use, since it does not
-     * affect the liveness of the node.
-     */
-    if(!is_data_node(use))
-      continue;
+static void compute_liveness(be_lv_t *lv)
+{
+	struct _lv_walker_t w;
+	w.lv   = lv;
+	w.data = bitset_malloc(get_irg_last_idx(lv->irg));
+	irg_walk_graph(lv->irg, liveness_for_node, NULL, &w);
+	bitset_free(w.data);
+}
 
-    /* Get the block where the usage is in. */
-    use_block = get_nodes_block(use);
+/* Compute the inter block liveness for a graph. */
+be_lv_t *be_liveness(ir_graph *irg)
+{
+	be_lv_t *lv = xmalloc(sizeof(lv[0]));
+
+	memset(lv, 0, sizeof(lv[0]));
+	FIRM_DBG_REGISTER(lv->dbg, DBG_MODULE);
+	lv->irg = irg;
+	lv->nodes = bitset_malloc(2 * get_irg_last_idx(irg));
+	lv->hook_info.context = lv;
+	lv->hook_info.hook._hook_node_info = lv_dump_block;
+	register_hook(hook_node_info, &lv->hook_info);
+	phase_init(&lv->ph, "liveness", irg, PHASE_DEFAULT_GROWTH, lv_phase_data_init);
+	compute_liveness(lv);
+
+	return lv;
+}
 
-    /*
-     * If the use is a phi function, determine the corresponding block
-     * through which the value reaches the phi function and mark the
-     * value as live out of that block.
-     */
-    if(is_Phi(use)) {
-      int i, n;
+void be_liveness_recompute(be_lv_t *lv)
+{
+	unsigned last_idx = get_irg_last_idx(lv->irg);
+	if(last_idx >= bitset_size(lv->nodes)) {
+		bitset_free(lv->nodes);
+		lv->nodes = bitset_malloc(last_idx * 2);
+	}
+
+	else
+		bitset_clear_all(lv->nodes);
+
+	phase_free(&lv->ph);
+	phase_init(&lv->ph, "liveness", lv->irg, PHASE_DEFAULT_GROWTH, lv_phase_data_init);
+	compute_liveness(lv);
+}
 
-      /* Mark the node as a phi operand, since a use by a phi was found. */
-      /* get_node_live_info(irn)->is_phi_op = 1; */
 
-      for(i = 0, n = get_irn_arity(use); i < n; ++i) {
-        if(get_irn_n(use, i) == irn) {
-          ir_node *pred_block = get_nodes_block(get_irn_n(use_block, i));
-          live_end_at_block(irn, pred_block, visited, 0);
-        }
-      }
-    }
+void be_liveness_free(be_lv_t *lv)
+{
+	unregister_hook(hook_node_info, &lv->hook_info);
+	phase_free(&lv->ph);
+	bitset_free(lv->nodes);
+	free(lv);
+}
 
-    /*
-     * Else, the value is live in at this block. Mark it and call live
-     * out on the predecessors.
-     */
-    else if(def_block != use_block) {
-      int i, n;
+void be_liveness_remove(be_lv_t *lv, ir_node *irn)
+{
+	unsigned idx = get_irn_idx(irn);
+	struct _lv_walker_t w;
+
+	/*
+	 * Removes a single irn from the liveness information.
+	 * Since an irn can only be live at blocks dominated by the block of its
+	 * definition, we only have to process that dominance subtree.
+	 */
+	w.lv   = lv;
+	w.data = irn;
+	dom_tree_walk(get_nodes_block(irn), lv_remove_irn_walker, NULL, &w);
+	if(idx <= bitset_size(lv->nodes))
+		bitset_clear(lv->nodes, idx);
+}
 
-      mark_live_in(use_block, irn);
+void be_liveness_introduce(be_lv_t *lv, ir_node *irn)
+{
+	struct _lv_walker_t w;
+	w.lv   = lv;
+	w.data = bitset_malloc(get_irg_last_idx(lv->irg));
+	liveness_for_node(irn, &w);
+	bitset_free(w.data);
+}
 
-      for(i = 0, n = get_irn_arity(use_block); i < n; ++i) {
-        ir_node *pred_block = get_nodes_block(get_irn_n(use_block, i));
-        live_end_at_block(irn, pred_block, visited, 1);
-      }
-    }
-  }
+void be_liveness_update(be_lv_t *lv, ir_node *irn)
+{
+	be_liveness_remove(lv, irn);
+	be_liveness_introduce(lv, irn);
+}
 
-  del_pset(visited);
+static void lv_add_missing_walker(ir_node *irn, void *data)
+{
+	struct _lv_walker_t *w = data;
+	if(!is_Block(irn) && !bitset_contains_irn(w->lv->nodes, irn)) {
+		liveness_for_node(irn, w);
+	}
 }
 
-static int cmp_irn_live(const void *a, const void *b, size_t size)
+void be_liveness_add_missing(be_lv_t *lv)
 {
-  const irn_live_t *p = a;
-  const irn_live_t *q = b;
+	struct _lv_walker_t w;
+	w.lv   = lv;
+	w.data = bitset_malloc(get_irg_last_idx(lv->irg));
+	irg_walk_graph(lv->irg, lv_add_missing_walker, NULL, &w);
+	bitset_free(w.data);
+}
 
-  return !(p->block == q->block && p->irn == q->irn);
+static void lv_check_walker(ir_node *bl, void *data)
+{
+	struct _lv_walker_t *w = data;
+	be_lv_t *lv    = w->lv;
+	be_lv_t *fresh = w->data;
+
+	struct _be_lv_info_t *curr = phase_get_irn_data(&lv->ph, bl);
+	struct _be_lv_info_t *fr   = phase_get_irn_data(&fresh->ph, bl);
+
+	if(!fr && curr && curr[0].u.head.n_members > 0) {
+		unsigned i;
+
+		ir_fprintf(stderr, "%+F liveness should be empty but current liveness contains:\n", bl);
+		for(i = 0; i < curr[0].u.head.n_members; ++i) {
+			ir_fprintf(stderr, "\t%+F\n", get_idx_irn(lv->irg, curr[1 + i].u.node.idx));
+		}
+	}
+
+	else if(curr) {
+		unsigned n_curr  = curr[0].u.head.n_members;
+		unsigned n_fresh = fr[0].u.head.n_members;
+
+		unsigned i;
+
+		if(n_curr != n_fresh) {
+			ir_fprintf(stderr, "%+F: liveness set sizes differ. curr %d, correct %d\n", bl, n_curr, n_fresh);
+
+			ir_fprintf(stderr, "current:\n");
+			for(i = 0; i < n_curr; ++i) {
+				struct _be_lv_info_node_t *n = &curr[1 + i].u.node;
+				ir_fprintf(stderr, "%+F %u %+F %s\n", bl, i, get_idx_irn(lv->irg, n->idx), lv_flags_to_str(n->flags));
+			}
+
+			ir_fprintf(stderr, "correct:\n");
+			for(i = 0; i < n_fresh; ++i) {
+				struct _be_lv_info_node_t *n = &fr[1 + i].u.node;
+				ir_fprintf(stderr, "%+F %u %+F %s\n", bl, i, get_idx_irn(lv->irg, n->idx), lv_flags_to_str(n->flags));
+			}
+		}
+	}
 }
 
-void be_liveness(ir_graph *irg)
+void be_liveness_check(be_lv_t *lv)
 {
-  irg_live_info_t *live_info = get_irg_live_info(irg);
-  if(live_info->live)
-    del_set(live_info->live);
+	struct _lv_walker_t w;
+	be_lv_t *fresh = be_liveness(lv->irg);
 
-  live_info->live = new_set(cmp_irn_live, 8192);
-  irg_walk_graph(irg, liveness_for_node, NULL, NULL);
+	w.lv   = lv;
+	w.data = fresh;
+	irg_block_walk_graph(lv->irg, lv_check_walker, NULL, &w);
+	be_liveness_free(fresh);
+}
+
+
+static void lv_dump_block_walker(ir_node *irn, void *data)
+{
+	struct _lv_walker_t *w = data;
+	if(is_Block(irn))
+		lv_dump_block(w->lv, w->data, irn);
+}
+
+
+/* Dump the liveness information for a graph. */
+void be_liveness_dump(const be_lv_t *lv, FILE *f)
+{
+	struct _lv_walker_t w;
+
+	w.lv   = (be_lv_t *) lv;
+	w.data = f;
+	irg_block_walk_graph(lv->irg, lv_dump_block_walker, NULL, &w);
+}
+
+/* Dump the liveness information for a graph. */
+void be_liveness_dumpto(const be_lv_t *lv, const char *cls_name)
+{
+	FILE *f;
+	char buf[128];
+	ir_snprintf(buf, sizeof(buf), "%F_%s-live.txt", lv->irg, cls_name);
+	if((f = fopen(buf, "wt")) != NULL) {
+		be_liveness_dump(lv, f);
+		fclose(f);
+	}
+}
+
+/**
+ * Walker: checks the every predecessors of a node dominate
+ * the note.
+ */
+static void dom_check(ir_node *irn, void *data)
+{
+	int *problem_found = data;
+
+	if(!is_Block(irn) && irn != get_irg_end(get_irn_irg(irn))) {
+		int i, n;
+		ir_node *bl = get_nodes_block(irn);
+
+		for(i = 0, n = get_irn_arity(irn); i < n; ++i) {
+			ir_node *op     = get_irn_n(irn, i);
+			ir_node *def_bl = get_nodes_block(op);
+			ir_node *use_bl = bl;
+
+			if(is_Phi(irn))
+				use_bl = get_Block_cfgpred_block(bl, i);
+
+			if(get_irn_opcode(use_bl) != iro_Bad
+			     && get_irn_opcode(def_bl) != iro_Bad
+			     && !block_dominates(def_bl, use_bl)) {
+				ir_fprintf(stderr, "Verify warning: %+F in %+F must dominate %+F for user %+F (%s)\n", op, def_bl, use_bl, irn, get_irg_dump_name(get_irn_irg(op)));
+				*problem_found = 1;
+			}
+		}
+	}
+}
+
+/* Check, if the SSA dominance property is fulfilled. */
+int be_check_dominance(ir_graph *irg)
+{
+	int problem_found = 0;
+
+	irg_walk_graph(irg, dom_check, NULL, &problem_found);
+
+	return !problem_found;
+}
+
+pset *be_liveness_transfer(const arch_env_t *arch_env, const arch_register_class_t *cls, ir_node *irn, pset *live)
+{
+	int i, n;
+	ir_node *x;
+	FIRM_DBG_REGISTER(firm_dbg_module_t *dbg, DBG_MODULE);
+
+	DEBUG_ONLY(
+		DBG((dbg, LEVEL_1, "%+F\n", irn));
+		for(x = pset_first(live); x; x = pset_next(live))
+			DBG((dbg, LEVEL_1, "\tlive: %+F\n", x));
+	)
+
+	/* You should better break out of your loop when hitting the first phi function. */
+	assert(!is_Phi(irn) && "liveness_transfer produces invalid results for phi nodes");
+
+	if(arch_irn_consider_in_reg_alloc(arch_env, cls, irn)) {
+		ir_node *del = pset_remove_ptr(live, irn);
+		assert(irn == del);
+	}
+
+	for(i = 0, n = get_irn_arity(irn); i < n; ++i) {
+		ir_node *op = get_irn_n(irn, i);
+
+		if(arch_irn_consider_in_reg_alloc(arch_env, cls, op))
+			pset_insert_ptr(live, op);
+	}
+
+	return live;
+}
+
+pset *be_liveness_end_of_block(const be_lv_t *lv, const arch_env_t *arch_env, const arch_register_class_t *cls, const ir_node *bl, pset *live)
+{
+	int i;
+	be_lv_foreach(lv, bl, be_lv_state_end, i) {
+		ir_node *irn = be_lv_get_irn(lv, bl, i);
+		if(arch_irn_consider_in_reg_alloc(arch_env, cls, irn))
+			pset_insert_ptr(live, irn);
+	}
+
+	return live;
+}
+
+pset *be_liveness_nodes_live_at(const be_lv_t *lv, const arch_env_t *arch_env, const arch_register_class_t *cls, const ir_node *pos, pset *live)
+{
+	const ir_node *bl = is_Block(pos) ? pos : get_nodes_block(pos);
+	ir_node *irn;
+
+	be_liveness_end_of_block(lv, arch_env, cls, bl, live);
+	sched_foreach_reverse(bl, irn) {
+		/*
+		 * If we encounter the node we want to insert the Perm after,
+		 * exit immediately, so that this node is still live
+		 */
+		if(irn == pos)
+			return live;
+
+		be_liveness_transfer(arch_env, cls, irn, live);
+	}
+
+	return live;
 }